CBS and Viacom now plan to merge as soon as early December, the two media companies said Monday, setting in motion the last steps to yet another consolidation in the traditional media sector.

The two companies, which will be known as ViacomCBS once the deal is complete, said the pact had secured the approval of National Amusements Inc., the movie-exhibition chain controlled by the Redstone family that holds the majority of voting stock in both concerns.

Shari Redstone, daughter of media entrepreneur Sumner Redstone, will oversee the businesses for National Amusements. But day to day leadership will be put in the hands of Bob Bakish, the Viacom CEO. Joe Ianniello, the CBS CEO, is set to manage the majority of the CBS assets.

The companies had previously indicated their merger would be completed before the end of 2019.